The present invention relates to a retaining member for retaining an engine block heater in an engine bore, and more particularly, a quick-release retaining clip, providing freedom of orientation for a cartridge-style heater relative to the engine bore.
Dry or cartridge-style heaters are widely adopted for use with automotive engines to warm engine blocks under cold or other inclement environmental conditions.
The dry heater provides a heating element that is received and secured in a bore drilled into the engine block at a location adjacent to a fluid passage or chamber within the engine. The bore serves to locate the heater and to protect the heater from the weather, dirt and grime that often effect an engine during vehicle operation. Once installed inside the bore, the heating element, upon connection to an electrical power source, radiates heats directly to the engine block from contact of the heater with walls that define an outer periphery of the bore. Heat transferred from the heater warms the engine block and ultimately warms the engine fluid (e.g. coolant or oil) within the engine.
Commonly, the heater is equipped with a fastener such as a bolt or a clip that retains the heater in the bore by fastening a portion of the heater extending outside the bore to an exterior surface of the engine block. Under one approach, the heater is commonly provided with a fixed flange that extends from the portion of the heater extending outside the bore. The flange supports an aperture that matches a corresponding aperture located on the surface of the engine block. Upon placement of the heater in the bore, the heater is oriented to align the apertures. A bolt or screw passes through the apertures to mount the flange flush against the exterior surface of the engine, thereby securing the heater in the bore.
Alternatively, the fixed flange is often a clip designed to be snapped over a machined embossment existing on the exterior surface of the engine block adjacent to the engine bore. Upon placement of the heater in the bore, the heater is oriented to align the clip with the embossment. The clip snaps over and frictionally engages the embossment to retain the heater within the bore.
These prior art heater retaining mechanisms often require rigid, fixed connections of the heater within or about the bore. Such connections complicate installation of the heater and removal of heater for repair or replacement. Often, because of the confined areas of the engine compartment, it is difficult for an operator to manipulate tools necessary to secure or remove the heater from the bore. Additionally, the same confined area in the engine compartment makes aligning the heater with the designated area on the engine difficult (e.g. aligning the flange on the heater with the aperture in the engine block to threadedly insert a screw to secure the heater).
Additionally, because the heater must be positioned in the bore in a manner undesirably constrained by the inherent limitations of the fastening mechanism, the orientation of a connector receptacle fixedly attached to the heater to receive an electrical connector supplying power from an external source to activate the heater is often compromised. As may be appreciated, the final orientation of the heater-mounted connector receptacle provided to receive the connection from the external power source is highly dependent upon the rotational orientation of the heater after the heater is mechanically secured in the bore. For example, the location of a fastening aperture or embossment on the engine block may vary significantly between engines, and even between engines of the same type due to manufacturing variances. Thus, the final orientation of the connector receptacle provided on a conventional heater may hamper the ease for a user to interconnect the heater to a connector from an external power source because the connector cannot be easily adapted to the connector receptacle of the heater because of interference between the connector and other engine components. To overcome this problem, multiple electrical connector configurations must be designed and inventoried to adopt to the orientation of the heater""s electrical connector receptacle, which varies depending on the heater""s retaining requirement within or about the bore and constraints imposed by the engine geometry.
Accordingly, an engine block heater is needed that overcomes the aforementioned difficulties and limitations.
To overcome the difficulties associated with block heaters, the present invention provides a specialized retaining member for securing a dry cartridge-style engine heater within an engine block of a conventional internal-combustion engine. The heater includes a generally annular cylindrical sleeve supporting an exterior heating surface that is releasably inserted into a bore adjacent to a fluid chamber within the engine block. The sleeve possesses a heating element designed to interconnect with an electrical connector received through a connector receptacle provided in a cap that defines a top portion of the sleeve. The electrical connector provides power from an external power source to operate the heater to warm the engine block and indirectly the fluid contained within the fluid chamber.
A quick-release retaining member attaches to the sleeve about a groove provided in an outer circumference of the sleeve or about the retaining member itself The retaining member is defined by a center portion from which extends a pair of legs. The space between the legs defines a center region designed to receive the sleeve therebetween. An arm, for attaching the retaining member to the engine block, extends from the center portion.
The retaining member is designed for the sleeve to occupy the center region defined by the legs. The legs frictionally engage the outer circumference of the sleeve to connect the heater to the retaining member. Even with the engagement by the legs, the sleeve maintains the ability to rotate between the legs and within the bore, upon the application of sufficient force to overcome the surface friction existing between contacting surfaces of the sleeve, the bore and the retaining member. The sleeve is rotatable even if the retaining member is attached to the engine. Likewise, the same rotatability permits the retaining member to be rotated about the sleeve to align the retaining member to a predetermined location on the exterior surface of the engine independent of the orientation of the heater within the engine bore.
Because the retaining member is not secured to the heater at a rigid, fixed point, the heater may rotate 360 degrees both inside the bore and within the member. The rotation provides freedom of orientation of the connector receptacle of the heater in infinite arrangements for positioning the heater to receive the electrical connector, which provides power to the heater from an external power source. Because of different engine configurations and confined space within engine compartments, flexibility in the orientation of the heater to receive the electrical connector simplifies interconnection between heater and the external power supply regardless of the engine configuration or vehicle model. Moreover, the quick-release nature of the retaining member improves installation and disengagement of the heater from the bore, tasks that could otherwise be difficult and time consuming to accomplish because of the tight confines of the engine compartment and low-observablity of the components therein resulting from the engine block""s geometry. Overall, the rotatability of the retaining member provides flexibility, not available with conventional heaters, to orient the heater to connect to the external power source, thereby enhancing accessibility of the heater to the ultimate user.